Sliding doors supported solely for substantially horizontal sliding movement are conventionally utilized within building interiors, such as office buildings, to separate various areas of the building. Such sliding doors are particularly desirable in commercial environments since the door does not protrude into adjacent hallways or workspaces, and hence permits more efficient utilization of adjacent spaces. A disadvantage associated with such sliding doors, however, is encountered when locking of the door, such as for privacy purposes, is desired. The force and motion required for opening and closing a sliding door is horizontally directed, in contrast to the typical rotary force and motion utilized with door handles mounted on swinging doors. When it is desired to permit selective locking of a sliding door for privacy purposes, the door is typically provided with a separate mechanism which requires separate manual manipulations. This is further complicated when the sliding door is provided with a latching bolt which moves vertically and protrudes outwardly from an upper or lower edge of the door, although this latter type of latching bolt is typically preferred since it provides greater flexibility in most use environments.
Pending U.S. application Ser. No. 10/424,260 illustrates therein a handle-latch assembly for a horizontal sliding door which addresses the above concerns by permitting sequential unlocking and opening of a horizontal sliding door by application of a single-direction force and motion to the door handle to facilitate egress. While the mechanism disclosed in this application represents a desirable approach with respect to improving on latching arrangements for sliding doors, nevertheless the aforementioned mechanism is not believed to provide a comprehensive overall solution, and the present invention is believed to provide additional improvements with respect thereto.
More specifically, this invention relates to an improved handle-latch assembly which mounts on a horizontal sliding door and couples to a vertically movable latch bolt which protrudes outwardly from one of the top or bottom edges of the door, and which enables the inside and outside handles of the door to be respectively used for moving the door in closing and opening directions, with the door also having a manual lock actuator on the inside of the door and an optional key-lock actuator on the outside of the door, whereby latching of the door in the closed position requires a deliberate manual manipulation of either the inner lock actuator or the outer key actuator. The mechanism, however, permits sequential unlocking and opening of the door from the inside thereof solely by application of a generally single horizontally-directed force to the inner handle, whereas when the door is in the closed and latched position it can be opened from the outside thereof only by first manually releasing the lock through utilization of the separate key actuator. The handle-latch mechanism includes cooperating linkages which facilitate the above functions, and which ensure that these linkages and specifically the locking linkage is automatically reset into its unlocked position whenever the locked door is opened from the inside thereof due to manipulation of the inner handle.
Other objects and purposes of the invention will be apparent to persons familiar with constructions of this general type upon reading the following specification and inspecting the accompanying drawings.
Certain terminology will be used in the following description for convenience in reference only, and will not be limiting. For example, the words “upwardly”, “downwardly”, “rightwardly” and “leftwardly” will refer to directions in the drawings to which reference is made. The words “inwardly” and “outwardly” will refer to directions toward and away from, respectively, the geometric center of the door or designated parts of the door handle and locking mechanism. The words “inside” and “outside” will refer to opposite sides of the door, although it will be appreciated that these terms as they are used in relationship to the invention and its orientation with respect to the door can obviously be reversed. Said terminology will include the words specifically mentioned, derivatives thereof, and words of similar import.